Board-to-board power connector for a projection device

ABSTRACT

A projection device is disclosed, wherein the projection device includes a first circuit board, a second circuit board positioned in a spaced-apart relation to the first circuit board, a first connector extending from the first circuit board generally linearly toward the second circuit board, and a second connector extending from the second circuit board generally linearly toward the first circuit board, wherein the first connector and the second connector are coupled together to form an electrically conductive pathway between the first circuit board and the second circuit board.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of and claims priority to U.S.patent application Ser. No. 10/860,558, filed Jun. 2, 2004, entitled“Board-to-Board Power Connector for a Projection Device,” which claimspriority to U.S. Provisional Patent Application No. 60/475,568, filedJun. 2, 2003. The disclosures of these applications are herebyincorporated by reference in their entirety for all purposes.

TECHNICAL FIELD

The present invention relates generally to the electrical connection ofone circuit board to another circuit board in a projection device.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure is illustrated by way of example and not by way oflimitation in the figures of the accompanying drawings, in which thelike references indicate similar elements and in which:

FIG. 1 is a schematic illustration of an embodiment of a projectiondevice.

FIG. 2 is an isometric view of an assembly of electrical and opticalcomponents of an embodiment of a projection device, showing anembodiment of a board-to-board connector for connecting spaced-apartfirst and second circuit boards.

FIG. 3 is a magnified isometric view of a first connector of theembodiment of FIG. 2.

FIG. 4 is a magnified isometric view of a second connector of theembodiment of FIG. 2.

FIG. 5 is a magnified isometric view of the first connector of theembodiment of FIG. 2, showing a schematic outline of an alternate shroudconfiguration.

DETAILED DESCRIPTION

A projection device or image-generating device 10 is illustratedschematically in FIG. 1. The projection device 10 may be adapted toproject an image on a display surface, including, but not limited to, ascreen, a wall, or other viewing surface or area. As used herein, aprojection device or image-generating device may include any suitabledisplay device or image projector, including, but not limited to, adigital projector, a liquid crystal display (LCD) projector, a digitallight processing projector, etc.

In its most basic form, the projection device 10 includes a light source(or lamp) 12 and an optical engine (or image engine) 14 contained withinan enclosure, such as a casing 13. The light source 12 may be adapted toproduce a beam of light and project the light towards the optical engine14, which may be configured to generate an image. The light source 12typically includes a lamp (not shown) positioned within a reflector (notshown) that is configured to direct most of the emitted light along theoptical path of the projection device 10. The light source 12 mayinclude any suitable type of lamp. Examples include, but are not limitedto, metal halide lamps and ultra-high-pressure (UHP) arc lamps, etc. Theemitted light may also pass through one or more filters (not shown),such as an infrared (IR) or ultraviolet (UV) filter, to filter outunwanted parts of the emission spectra of the lamp.

Light produced from the light source 12 may be channeled through aninterface tube or spacer 16 to optical engine 14. The optical engine 14may include filters, color wheels, lenses, mirrors, integrators,condensers, and other optical elements (not shown).

The optical engine 14 may include an image-producing element 18. Anysuitable image-producing element may be used. Examples include, but arenot limited to, digital micromirror devices (DMD) and LCD panels. Theimage-producing element 18 may be configured to project light toward oneor more mirrors, lenses and/or other optics, such as a projection lens22, which, in turn, may be configured to reflect light toward a displaysurface.

The projection device 10 typically includes one or more power sources20. The power source 20 is typically at least partially disposed on apower source circuit board, and may be linked to the light source 12,the image-producing element 18, and other components, such as a controlcircuit board within the projection device to provide power to thesecomponents.

Operation of light source 12 and other electronic components inprojection device 10 may increase the temperature of the projectiondevice 10 during use. If the temperature of the projection device 10exceeds critical limits, portions of the device may malfunction and/orhave a shorter life span. Maintaining temperatures within the device atoperating levels thus may prevent the device from malfunctioning and/orincrease the lifespan of components and parts. A blower system 24 maythus be provided to circulate ambient air through the projection deviceand eject circulated air, as depicted by lines 26, thus helping to coolprojection device components. The blower system 24 may include a blowerportion, such as a fan, wheel, or similar air mover, powered by a blowermotor.

FIG. 2 further illustrates various components within an exemplaryprojection device. As illustrated, the projection device includes apower circuit board 30 and a control circuit board 32. The power board30 typically is an electronic circuit board configured to regulate DCpower within the projection device. The control board 32 includeselectrical components configured to control the operation of theprojection device 10, such as various logic components. The depictedpower board 30 is configured to be positioned adjacent a first side ofcasing 13, and the depicted control board 32 is configured to bepositioned adjacent a second, opposing side of casing 13 in projectiondevice 10, such that the space between the power board 30 and thecontrol board 32 may accommodate electrical and/or optical components,and/or may admit the passage of a flow of cooling air.

The power board 30 is electrically connected to the control board 32 tosupply power to the control board 32 via a board-to-board connector 34.In many prior devices, the electrical connections between twospaced-apart circuit boards are achieved through the use of connectiondevices such as wire harnesses, spanning circuit boards and floatingconnectors. However, the wire harnesses, spanning circuit boards andfloating connectors may be bulky, and thus difficult to physicallyaccommodate within a small-sized projection device. Furthermore, suchbulky connection devices may disrupt the airflow through the projectiondevice.

Further, in small devices, the distance between power board 30 andcontrol board 32 may be less than the minimum manufacturable length forwire harnesses, even where the boards are separated as far apart aspractical in the device. Manufacturing limitations may cause the wireharness to be bulkier than necessary. Such bulky harnesses may interruptairflow and disrupt other components within the device. Similarly, straywires within the wire bundle may disrupt various operating components,such as the color wheel, within the projection device.

Additionally, such connection devices may be difficult to assemblewithin the confined space of the projection device. For example, thespace around the location of the connection may be difficult to accessor view during assembly. This may make it difficult to solder orotherwise connect the wires to each of the boards during assembly.Moreover, a partially-blind assembly process may make it difficult toadequately couple the wiring harness to each other, and/or to desiredlocations on the boards.

Furthermore, the location of the two circuit boards within a projectiondevice may be variable relative to each other due to manufacturingtolerances, thus potentially frustrating the use of precision matingconnectors that are often used in spanning circuit boards. Moreover, itmay be difficult due to the size of the projection device to allocatespace to floating connectors having retention screws that may need to betightened once the connection between the two boards is made.

In contrast to wire harnesses, spanning circuit boards and floatingharnesses, board-to-board connector 34 may be adapted to minimizedisruption of other components with the device and airflow within thedevice, while providing a precise connection of two electronic circuitboards. Further, the board-to-board connector may accommodate variationsin the position of the electronic circuit boards relative to each otherto accommodate manufacturing tolerances, shocks to the system such asbeing dropped onto a hard floor, etc.

Referring again to FIG. 2, board-to-board connector 34 may include afirst connector 36 and a second connector 38. The first connector 36 maybe coupled to the power board 30, as shown in more detail in FIG. 3, andthe second connector 38 may be coupled to the control board, as shown inmore detail in FIG. 4.

The first connector 36 includes a first plurality of leads 40, and thesecond connector 38 includes a second plurality of leads 42. The firstplurality of leads 40 terminate at a first connecting structure 44, andthe second plurality of leads 42 terminate in a complementary secondconnecting structure 46 configured to connect to the first connectingstructure 44. Any suitable type of connecting structure may be used forthe first connecting structure 44 and the second connecting structure46. Examples include, but are not limited to, male/female connectingstructures.

The plurality of leads 40 of the depicted first connector 36 extend awayfrom the power board 30 in a generally linear manner, and in a directiongenerally orthogonal to an interior face 47 of the power board 30.Likewise, the plurality of leads 42 of the depicted second connector 38extends away from the control board 32 in a generally linear manner, andin a direction generally orthogonal to an interior face 48 of thecontrol board 32. In this configuration, the first connecting structure44 and second connecting structure 46 easily connect to each other wherepower board 30 and control board 32 are arranged in a generally coplanarrelationship. However, it will be appreciated that the first connector36 and the second connector 38 may extend from the power board 30 andthe control board 32, respectively, at any other suitable angles,depending upon the relative orientations and positions of the powerboard 30 and control board 32 within projection device 10.

The linear configuration of the leads 40 and 42 of first connector 36and second connector 38, respectively, may occupy less space in theinterior of projection device 10 than connectors such as wire harnesses,which typically includes at least some bends. Thus, the use of connector34 may impede the flow of cooling air through the projection device 10to a lesser extent than wire harnesses and similar connectors.

The first plurality of leads 40 and second plurality of leads 42 eachhave sufficient length for the combined length of the plurality of leads40 and the plurality of leads 42 to bridge the space between the powerboard 30 and the control board 32 when first connecting structure 44 iscoupled with second connecting structure 46. The first and secondpluralities of leads 40, 42 may be made of a material rigid enough tosupport the first and second connecting structures 44, 46 in generallyfixed positions when the connecting structures are detached, yetflexible enough to allow the first and second pluralities of leads 40,42 to absorb variations in positions due to thermalexpansion/contraction, manufacturing tolerances, etc. It should be notedthat although each connector set in the illustrated embodiments includeten leads, either more or fewer leads may be used.

The first and second pluralities of leads 40, 42 may be furthersupported through an alignment shroud. The alignment shroud may guidethe connection of the power board to the control board, and also mayprovide additional insulation and protection to first and secondconnectors 36, 38. The alignment shroud may include a first shroudsegment, shown at 50 in FIG. 3, that partially or fully encloses firstconnector 36, and a second shroud segment, shown at 52 in FIG. 4, thatpartially or fully encloses second connector 38. The first and secondshroud segments 50, 52 may be configured to attach together, forexample, via a snap connection, when first connector 36 and secondconnector 38 are coupled together. Such alignment shrouds may help toensure precise alignment of the first connecting structure 44 with thesecond connecting structure 46 during assembly of projection device 10.Such alignment shrouds may further allow for positive engagement of thefirst and second connecting structures 44, 46 regardless of theease/difficulty of viewing the connection of the connecting structures44, 46 during assembly.

In some embodiments, the use of board-to-board connector 34 to join twospaced-apart circuit boards enables the first connector 36 and secondconnector 38 to be easily connected even where the connection process isa blind or semi-blind process. For example, after placing the powerboard 30 in a desired location and after installing any other desiredprojector components, the control board 32 may be positioned over thepower board 30 such that the second connecting structure 46 ispositioned directly opposite the first connecting structure 44. Then,second and first connecting structure 46 and 44 may be joined simply bypushing the control board 32 toward the power board 30. Therefore, firstconnector 36 may be coupled to second connector 38 in a fast andefficient manner, even where the connectors are located in areas thatare partially or totally obscured by other components, or difficult toaccess. Furthermore, as mentioned above, the first and secondpluralities of leads 40, 42 may be configured to have sufficientflexibility to accommodate positional variation of circuit boards ofdifferent devices during the assembly process. For example, once thealignment shrouds are interlocked, the leads may adapt and bend inaccordance with the positions of the connected boards.

FIG. 5 shows an alternate shroud configuration, generally at 150.Instead of having two separate shroud portions, such as the shroud shownin FIGS. 3-4, shroud 150 has a single-piece construction configured tohold both first connector 36 and second connector 38 within itsinterior. Shroud 150 may help to aid the alignment of the firstconnector 36 with the second connector 38 during projector deviceassembly. For example, the second connector 38 may be simply insertedinto shroud 150 as the second connector 38 is lowered toward the firstconnector 36. Shroud 150 then may function to guide the second connector38 into correct alignment with the first connector 36, even insituations in which the second connector 38 and first connector 36 arein blind locations within projection device 10.

The depicted connector 34 may occupy a minimum footprint within theprojection device compared to other connectors. The compactness ofconnector 34 enables reduction of the overall size of the projectiondevice 10 to sizes that may be difficult to achieve using ribbons orwire harnesses, spanning circuit boards and/or floating connectors.Furthermore, the use of connector 34 may allow separate circuit boardsto be placed at spaced-apart locations in a device to make room forother components between the boards. For example, in the depictedembodiment, the separation of power board 30 and control board 32 allowsvarious optical and/or electrical components, such as projection lens22, to be located between the boards. Additionally, the configuration ofthe board-to-board connector may offer less of an impediment to a flowof cooling air through the projection device than the other types ofconnectors discussed above.

Although the present exemplary embodiments illustrate the use of aboard-to board connector in a projection device, it should beappreciated that the board-to-board connector described herein may beused in any suitable device requiring compact and precise alignment oftwo circuit boards. Furthermore, although the present disclosureincludes specific embodiments, specific embodiments are not to beconsidered in a limiting sense, because numerous variations arepossible. The subject matter of the present disclosure includes allnovel and nonobvious combinations and subcombinations of the variouselements, features, functions, and/or properties disclosed herein. Thefollowing claims particularly point out certain combinations andsubcombinations regarded as novel and nonobvious. These claims may referto “an” element or “a first” element or the equivalent thereof. Suchclaims should be understood to include incorporation of one or more suchelements, neither requiring nor excluding two or more such elements.Other combinations and subcombinations of features, functions, elements,and/or properties may be claimed through amendment of the present claimsor through presentation of new claims in this or a related application.Such claims, whether broader, narrower, equal, or different in scope tothe original claims, also are regarded as included within the subjectmatter of the present disclosure.

1. A projection device, comprising: a first circuit board; a secondcircuit board positioned in a spaced-apart relation to the first circuitboard; a first connector extending from the first circuit boardgenerally linearly toward the second circuit board; and a secondconnector extending from the second circuit board generally linearlytoward the first circuit board, wherein the first connector and thesecond connector are coupled together to form an electrically conductivepathway between the first circuit board and the second circuit board. 2.The projection device of claim 1, further comprising a casing havingopposing interior sides, wherein first board is located adjacent oneopposing interior side of the casing and second board is locatedadjacent the other opposing interior side of the casing.
 3. Theprojection device of claim 1, wherein the first connector has a firstplurality of leads connected at one end to the first circuit board andat another end to a first connecting structure, and wherein the secondconnector has a second plurality of leads connected at one end to secondcircuit board and at another end to a second connecting structure, andwherein the second connecting structure is coupled to the firstconnecting structure.
 4. The projection device of claim 3, wherein thefirst plurality of leads are formed from a flexible material capable ofsupporting the first connecting structure in a generally fixed positionwhen disconnected from the second connecting structure, and capable offlexing under stress when connected to the second connecting structure.5. The projection device of claim 1, further comprising an opticalcomponent disposed between the first circuit board and the secondcircuit board.
 6. The projection device of claim 1, further comprisingan airflow passage between the first circuit board and the secondcircuit board, and wherein the first connector and second connectorbridge the airflow passage.
 7. The projection device of claim 1, furthercomprising a shroud at least partially covering at least one of thefirst connector and the second connector.
 8. A projection device,comprising: a casing having an interior; a first circuit board disposedwithin the interior; a first connector extending away from the firstcircuit board, wherein the first connector includes a plurality of firstleads connected at one end to the first circuit board and connected atanother end to a first connecting structure; a second circuit boarddisposed within the interior, wherein the second circuit board has aspaced-apart relation to the first circuit board; and a second connectorextending away from the second circuit board, wherein the secondconnector includes a plurality of second leads connected at one end tothe second circuit board and connected at another end to a secondconnecting structure, wherein the first connecting structure and secondconnecting structure are coupled together, and wherein the first leadsare configured to support the first connecting structure in a generallyfixed position relative to the first circuit board and the second leadsare configured to support the second connecting structure in a generallyfixed position relative to the second circuit board when the first andsecond connecting structures are disconnected.
 9. The projection deviceof claim 8, wherein the first circuit board is a power supply board, andwherein the second circuit board is a logic control board.
 10. Theprojection device of claim 8, further comprising an optical componentdisposed between the first circuit board and the second circuit board.11. The projection device of claim 8, further comprising an airflowpassage between the first circuit board and the second circuit board,and wherein the first connector and second connector bridge the airflowpassage.
 12. The projection device of claim 8, wherein the first circuitboard and the second circuit board are generally coplanar, wherein thefirst connector extends away from the first circuit board in a directiongenerally orthogonal to a face of the first circuit board, and whereinthe second connector extends away from the second circuit board in adirection generally orthogonal to a face of the second circuit board.13. The projection device of claim 8, further comprising a shroud thatat least partially surrounds at least one of the first connectingstructure and the second connecting structure.
 14. A projection device,comprising: a first circuit board; a first electrical connectorextending from the first circuit board in a direction generallyorthogonal to the first circuit board; a second circuit board disposedin a spaced-apart, generally coplanar relationship to the first circuitboard; a second electrical connector extending from the second circuitboard in a direction generally orthogonal to the second circuit board,wherein the second connector is coupled to the first connector; and anoptical system disposed between the first circuit board and the secondcircuit board.
 15. The projection device of claim 14, wherein the firstelectrical connector extends away from the first circuit board in agenerally linear configuration, and wherein the second electricalconnector extends away from the second circuit board in a generallylinear configuration.
 16. The projection device of claim 14, wherein thefirst connector has a first plurality of leads connected at one end tothe first circuit board and at another end to a first connectingstructure, and wherein the second connector has a second plurality ofleads connected at one end to second circuit board and at another end toa second connecting structure coupled to the first connecting structure.17. The projection device of claim 16, wherein the first plurality ofleads are formed from a flexible material capable of supporting thefirst connecting structure in a generally fixed position whendisconnected from the second connecting structure, and capable offlexing under stress when connected to the second connecting structure.18. The projection device of claim 14, further comprising an airflowpassage between the first circuit board and the second circuit board,and wherein the first connector and second connector bridge the airflowpassage.